My experience professionally has included a couple of restaurants. And that experience tells me that clients planning those establishments start with an anticipated seat count. How many patrons do you anticipate this establishment serving at any one time. Most jurisdictions and building authorities have specific square footage requirements based on seating capacity. They also have limits on seating capacity for many various types of establishments. You might want to start with your local folks, and find out what the local zoning says about seat counts, square footage, and parking requirements. For you will most certainly be required to provide parking for your patrons.